Improvement in erasive tablets



CHARLES N. BROWN, OF PROVIDENCE, RHODE ISLAND.

Specification forming part of Letters Patent No- 147,59*?, dated February 17, 1874; applica-tion filed January 23, 1874.

To all whom t may concern Be it known that I, C. N. BROWN, of Providence, in the countyiof Providence and in the State of Rhode Island, have invented certain new and useful Improvements in Erasive Tablets and Silicate Slate, and do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the let- Aters of reference' marked thereon, making a part of this specification.

My present invention is intended as an improvement upon the writing-tablet for which Letters Patent No. 144,950 were granted to me November 25, 1873. In this patent I claimed ribs raised on or attached to the leaves of an crasive tablet; but I find, by experiment, that small projections formed on or attached to the leaves of the tablet will answer the saine pun pose as the ribs extending` entirely across the leaf, and that such projections may be formed on or attached vto silicate slate, as well as to the ordinary erasive tablet. The nature of my 'nvention, therefore, consists in a silicate slate or erasive tablet provided with projections attached to or formed in the leaves thereof, for the purpose of preventing the rubbing together `of the writing-surfaces and consequent bluring of the writing, as will be hereinafter more ,fully set forth.

In the accompanying drawing, Figure lis a perspective view of a silicate slate or erasive tablet embodying my invention, and Fig. 2is

a section through the line :o of one of the leaves.

A A represent the leaves of a silicate slate or erasive tablet. Each leaf A is provided with a suitable number of small proj ections, a a,wliicl1, when the leaves are closed, will Aprevent the writing-surfaces from rnbbing together and obliterating or blurring the Writing. These projections may be raised upon one side of the leaf by impressing orindenting the other side by means of dies fitted for the purpose; or they may be formed in or of the material of which the leaves are made 5 or the projections may be made separate, of wood, metal, or any other suitable material, and attached in any convenient manner to the leaves; or drops of glue or wax prepared for the purpose maybe deposited on the leaves, and answer the same object.

- Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

An erasive or silicate-slate tablet provided with projections a a, attached to or formed in the leaves thereof, substantially as and for the purposes herein set forth. u

In testimony that I claim the foregoing, I have hereunto set my hand this 30th day of December, 1873.

CHARLES N. BROXVN. IVitnesses:

ALFRED RICKARD,

VILLIAM W. RICHARD. 

